Water Table Concerns for Storm Drains and Culverts
Storm drain and culvert pipe installations can be sensitive to the presence of a water table in the backfill and surrounding soil. Soils placed and compacted in the pipe envelope need to be stable in the presence of water. The soil-pipe interaction analysis needs to account for the buoyant effect and impact on the passive soil pressure that a water table has on the soils used in the installation. For a rigid pipe installation these factors are somewhat insignificant, since the majority of the strength is resident within the structure of the rigid pipe material. But, for a flexible pipe, the majority of the strength is built into the soil envelope which is impacted directly and extensively by the presence of a water table.